First Steps With CoDeSys V23

First Steps with CoDeSys

Last update: 05.03.2004


3S - Smart Software Solutions GmbH First Steps with CoDeSys V23.doc Page 2 of 10

CONTENT

1 STARTING CODESYS 3

2 WRITING THE FIRST PROGRAM 3

3 A VISUALIZATION FOR THIS 7

4 START THE TARGET SYSTEM 9

5 SETTINGS FOR ESTABLISHING THE CONNECTION 9

6 START THE PROJECT 9

7 CONTINUING FROM HERE 10



1 Starting CoDeSys

Start the CoDeSys programming system with Start -> Programs -> 3S Software -> CoDeSys V2.3 -> CoDeSys V2.3

2 Writing the First Program

• Task: A running machine is to be observed by a machine operator. Correct running must be confirmed at specified intervals. If there is no confirmation, a warning is first issued, shortly after which the machine will be stopped. The machine moves an arm along a rectangular path, and completed circuits are to be counted.

• Creating a New Project Starting is easy. Create a new project with the command File -> New.

• Target Settings For our first project please select the entry which fits to your runtime system as target in the combo box ‘Configuration’, e.g. CoDeSys SP for Windows NT Realtime

• The PLC_PRG POU In the New POU dialog select the language of the POU FBD (Function Block Diagram) and retain the settings Type Program and Name PLC_PRG. PLC_PRG is a special POU which is cyclically called and executed by the run-time system in operation.

• Declaration of the Confirmation Switch We will start with the confirmation switch. Mark the three question marks ??? in the first network, and type in the name of the switch (e.g. Observer). Now press the right-arrow key. The dialog which appears for the declaration of variables contains the Name Observer and the Type BOOL. Alter the Class to VAR_GLOBAL (for global variables). The variable is entered in the object for global variables with OK. The following text appears there:

VAR_GLOBAL

Observer: BOOL; END_VAR

• Rising Edge of the Confirmation Switch Everything is OK if the operator is there and confirms correct sequence of operation. That is, if the switch changes from the off state (FALSE) to the on state (TRUE), known as the rising edge, or from on to off, called the falling edge. We will start by determining the rising edge, i.e. whether the switch changes from FALSE to TRUE. For this, we return to the PLC_PRG POU. Mark the location behind the Observer variable, so that a rectangular marking appears. Execute the Box command through the quick menu (right mouse button). A box for the AND operator is inserted and the name is marked. Now call the input assistant with F2. You get a dialog, which offers all available operators. Select first the Standard Function Blocks category and there the trigger function block R_TRIG, which belongs to the standard.lib. R_TRIG reports the rising edges of boolean value, which in this case is our switch. An instance (data copy) of R_TRIG must be created. To do this, replace the three question marks ??? which appear on top of the inserted box by the instance name (e.g. Trig1). After that either click with the left mouse button behind the function block or press the right-arrow key. The Declare variables dialog will appear, where the Class VAR (for local variables), the Name Trig1 and the Type R_TRIG are already entered. Press OK to enter the variable into the declaration segment of the POU.



• Falling Edge of the Confirmation Switch Mark the location behind the function block (rectangular marking), execute the Box command via the quick menu, and alter the designation AND to OR (logical or). Mark the line of the second input of the OR-operator and insert a Box of Type F_TRIG for the falling edge, having the instance Name Trig2. Mark the three question marks in front of the Trig2 function block, press the <F2> function key (input assistance) and select the Observer variable in the Global Variables category of the dialog which appears.

• Time Monitoring, First Part Insert a Box of Type TOF (switch-off delay) with the Name Timer1 behind the OR-operator using the quick menu. Replace the three question marks at the PT input with the time constant T#10s for 10 seconds. (The time can later be increased, after successful tests.)

• Issue Warning Insert an Assignment behind the Q output of the Timer1 function block using the quick menu. Replace the three question marks with the variable name Warning. In the declaration of variables, enter the Class VAR_GLOBAL and the type BOOL. So that the warning is indeed properly given, mark the first position on the assignment and execute the Negate command via the quick menu. This causes the boolean signal to be inverted, and is displayed by means of a small circle.

• Set the Stop Signal After Exceeding the Second Time Limit Create another network with the menu command Insert->Network (after). Use the quick menu to add a Box of Type TON (function_block, switch-on delay) with the Name Timer2 into the second network. Allocate the variable Warning to the IN input with the aid of the <F2> key, and the time constant T#5s to the PT input. After the Timer2 function block we need an Assignment again, this time to the variable Stop (Class VAR_GLOBAL).

• Insert POU for the Machine Insert another POU with the Name Machine, of Type program and with the Language SFC (Sequential Function Chart) into the object organizer (the left hand area of CoDeSys), under



POUs, using the quick menu command Add object. The initial diagram of a POU in SFC consists of a step "Init", and of a subsequent transition "Trans0" followed by a jump back to Init.

• Specify the Machine’s Sequence Each phase in the operation of our machine requires a step. Mark the transition Trans0 in such a way that a dotted frame appears round Trans0, and use the quick menu to select the command Step-Transition (after). Repeat this procedure five times. If you click directly on the name of a transition or of a step it will be marked in blue and can be altered. The step after the Init step should be called Go_Right, and the following steps Go_Down, Go_Left, Go_Up and Count.

• Programming the First Step After a double click on the Go_Right step you will be asked about the desired Language. Select ST (structured text) and a separate window appears for the action associated with this step. The machine arm should be moved in the X-direction. The program line reads: X_pos := X_pos + 1 ;

Complete the line with a return, and declare the variable X_pos having Type INT for integer. A small triangle appears in the upper left hand corner of the step to indicate that this step has been programmed.

• Programming the Next Steps

Repeat this procedure for the other steps with altered program lines, and as you do so declare the variables Y_pos and Counter of Type INT. In the Go_Down step Y_pos := Y_pos + 1 ;

In the Go_Left step X_pos := X_pos - 1 ; In the Go_Up step Y_pos := Y_pos - 1 ; In the Count step Counter := Counter + 1 ; • Specify Transitions

Transitions are the conditions for progressing from one phase to the next. Overwrite the first transition after Init with the variable Start. In the declaration of variables enter the Class VAR_GLOBAL and the Type BOOL. The machine thus starts to run when the start switch is pressed. The second transition contains the condition X_Pos = 100, so that when the X-position has reached the value 100 the next phase starts. The third contains the condition Y_pos = 50, the fourth contains the condition X_pos = 0, the fifth contains the condition Y_pos = 0 and the sixth contains the condition TRUE (continue immediately after a single execution)



• Halt Processing at Stop

Go back to the PLC_PRG POU and insert a third network. Replace the question marks by the variable Stop, and after that select the Return command from the context menu. The Return has the effect of leaving the PLC_PRG POU when Stop is set.

• Call Machine POU Insert another network, set the focus there and execute in the command Box from the context menu. The "AND" in the box is marked already. Press <F2> and in the input assistant dialog which appears, select the machine POU in the User defined Programs category. This completes the programming.



• Build Project

Build the project with the menu command Project->Rebuild all, or the <F11> function key. In the message window at the bottom right, „0 errors„ should be reported after the build procedure. If not, check that all the entries have been correctly made. The reported error may also help.

3 A Visualization for This

• Create Visualization In the object organizer at the bottom left select the third tab from the left, named Visualization.

• Use the object organizer’s quick menu to call the Add object command. Give the visualization object a Name, such as Observation. The visualization should finally look like this:



• Draw Visualization Element Let’s start with the confirmation switch (the rectangle with the text OK in the figure). Select the symbol for Rectangles from the toolbar. Press the left hand mouse key in the visualization editor, hold it down, and draw a rectangle with it. Release the mouse key when it has reached the desired form and size.

• Configure the First Visualization Element With a double click on the rectangle, the configuration dialog will appear. In the Contents field of the Text Category write the text OK. Select the Variables Category, click in the Change Color field and call up the input assistance with the <F2> function key. Give a double click to the point in the right hand half of the dialog box, and the global variable will appear. Select the Observer variable. The field now contains .Observer

After this, select the Colors Category in the configuration dialog, and click on the Inside button in the Color area. Select a color (e.g. light blue). Then select another color with the Inside button in the Alarm color area (e.g. blue). In the Input Category select the Toggle variable point and again enter the variable Observer into the field behind it with <F2>. Leave the configuration dialog. This causes the rectangle to be colored light blue during running operation when the Observer variable is in the FALSE state, and blue when it is in the TRUE state. With each mouse click the state is changed from TRUE to FALSE, or the other way around.

• Expand Visualization

Draw a circle for the warning, and configure it with the following values: Text Category, Contents field with Warning Variable Category, Color change field with .Warning Colors Category, Color area using Inside with color grey, and Alarm color with red. Copy the circle you have created using the menu command Edit -> Copy and insert another one with the menu command Edit -> Paste. Alter the following values in the new circle: Text Category, Contents field with the new entry Stop

Variable Category, Color change field with the new entry .Stop

Draw a rectangle for the start of the machine and configure it with the following values: Text Category, Contents field with Start



Variable Category, Color change field with .Start Input Category, select the point Toggle variable Input Category, behind Toggle variable, enter .Start in the field Colors Category, Color area using Inside with color red, and Alarm color with green. Draw a rectangle for the counter and configure it with the following values:

Text Category, Contents field with Counter : %s (%s functions as a place holder for the variable value) Variable Category, Textdisplay field with Machine.Counter Draw a rectangle for the machine and configure it with the following values: Absolute movement Category, X-Offset field with Machine.X_pos Absolute movement Category, Y-Offset field with Machine.Y_pos Colors Category, Color area using Inside with color blue. If you like, you can draw two large rectangles around the two areas for observation and for the

machine, enter Observation (or Machine) as the Contents in the Text Category, and select the Vertical alignment bottom. Using the quick menu command Send to back place the rectangle behind the existing elements.

The following steps 4,5,6 only can be executed, if a runtime system has been installe, which fits to the target settings in CoDeSys. Otherwise you have the possibility to work in simulation mode. In this case continue now with Step 6 for logging in and starting the project.

4 Start the Target System

Start the target runtime system. (Please regard that in case of using the runtime system CoDeSys SP RTE this is only possible on Windows NT 4.0, Windows 2000 or Windows XP. Here you will get the icon of CoDeSys SP RTE in the status bar. Click on this with the right mouse button and choose the command 'Start System'.)

5 Settings for Establishing the Connection

• A small number of settings must be made before we can establish the connection to the target computer. For this purpose carry out the menu command Online -> Communication parameters.

• Select the button New to configure the connection to your target system. Enter an appropriate name for the connection at the new dialog and select a connection; in case of CoDeSys SP RTE Shared memory (Kernel). If the target computer is your local computer you can now close the dialog with OK. If the target computer is not your local computer, you have to change the value 'localhost' to the Internet address or the target name of the target computer. After that also close the communications parameters dialog with OK.

6 Start the Project

• The connection to the target computer will be established using the menu command Online -> Login from the CoDeSys development environment, and

• with Online -> Run your program will be started on the target computer. (If you want to work in simulation mode, the option 'Online' 'Simulation' must be activated).

• By means of the visualization you can now start the machine and operate the confirmation switch.



7 Continuing From Here

• It is now up to you to create and use further applications. For further information please see the Online Help and the Users Manual for the CoDeSys Programming System. We wish you every success!

Documents

First Steps With CoDeSys V23